Two points I’m sure everyone is curious about. How donors were screened, and any adverse side effects reported:

The authors describe the screening process this way:

Donors (<60 years of age) were volunteers who were initially screened using a questionnaire addressing risk factors for potentially transmissible diseases. Donor feces were screened for parasites (including Blastocystis hominis and Dientamoeba fragilis), C. difficile, and enteropathogenic bacteria. Blood was screened for antibodies to HIV; human T-cell lymphotropic virus types 1 and 2; hepatitis A, B, and C; cytomegalovirus; Epstein–Barr virus; Treponema pallidum; Strongyloides stercoralis; and Entamoeba histolytica. A donor pool was created, and screening was repeated every 4 months. Before donation, another questionnaire was used to screen for recent illnesses.

As far as adverse events were concerned:

Immediately after donor-feces infusion, most patients (94%) had diarrhea. In addition, cramping (31%) and belching (19%) were reported (Table 2). In all patients, these symptoms resolved within 3 hours.

During follow-up, three patients who were treated with donor feces (19%) had constipation. No other adverse events related to study treatment were reported.

For patients afflicted with C. diff, but who cannot get past the `ick’ factor of receiving donor feces, there may be hope on the horizon.

Researchers in Ontario, Canada have developed a `synthetic stool’, containing 33 types of `good’ bacteria, they call RePOOPulate.

Results of limited testing (only two patients) were recently published in the open access journal Microbiome.

Conclusion

This proof-of-principle study demonstrates that a stool substitute mixture comprising a multi-species community of bacteria is capable of curing antibiotic-resistant C. difficile colitis. This benefit correlates with major changes in stool microbial profile and these changes reflect isolates from the synthetic mixture.

For now, fecal transplants are not FDA approved, and questions remain over the safety of using donor feces.

If synthetic stools products can be shown to have a Darwinian advantage over C. diff bacteria in the human gut, it would go a long ways towards eliminating any concerns over the `origins of feces’.